Internal-combustion engine



Dem-4 1923. 1,476,307 v c. J. TOTH INTERNAL COMBUSTION ENGINE FiledApril 15 1922 2 Sheets-Sheet l ilb wuenlioz A: am a cum} 0 Dec. 4, 1923.1,476,307 0. J. TTH

INTERNAL COMBUSTION ENGINE Filed April 15. 1922 2 Sheets-Sheet 2 N N N NWIKEQQ N\ @1400 toz as A aw Patented iDecJl,

CHARLES J. T'IH, E STAPLETGN, NEW YQRIK, ASSIGETUR T0 INTERE'JQTIUNMTEOGESS AND ENGINEERHIG CORPORATION, OF NEW YORK, i l. A GGRPZZJRATIGET@F QTEW IIITlERNAL-COHBU STION ENGKHE.

Application filed April 35, 1922. Serial lio. 553,054.

To all whom it may concern.

Be it known that 1, CHARLES J. Tom a citizen of the Republic of Uruguay,and resident of Stapleton, New York city, county of Richmond, and Stateof New York, have invented certain new and useful Improvements inInternal-Combustion Engines, of which the following is a specification.

The invention relates to improvementsv W in internal combustion'engines,and includes among its objects the provision of novel structures ofgreat simplicity and high economy and efliciency. 1

In accordance with one form of the in- 5 vention a pair of pistons. aremounted in a cylinder to move in such a manner as to leave a combustionchamber or working cylinder space, of varying'volume, between them.Valve means are so constructed and 29 operated as to open communicationbetween an inlet opening and this spaceand between an exhaust openingand this space,

at suitable times.

. More hroadly speaking, a pair of roletively movable members aremounted in the cylinder, at least one of which serves as a movablepiston, the s ace between these members being connects at suitable timesto the inlet and the exhaust. The combus- 30. tion space between therelatively movable members isjvaried in volume in such a mannet thatvarious desirable efiects are obtained. Une of these eflects is that thevolume of this space increases to a greater maximum during the workingor expansion stroke of the engine than it does during the admissionstroke. The expanding charge performs useful work throughout itsexpansion. Accordingly the expansion of 40 the compressed charge afterexplosion or ignition of the same will proceed i to a a greater degreethan is possible with engines in which the maximum volume of thecylinder is the same during admission as during expansion; Increasedoutput and economy result from this arrangement.

In the preferred construction two pis tons are employed, one connectedto one crank shaft" rotating at one speed and the 59 other to a secondcrank shaft rotating at a difi'erent speed. Both crank shafts arepreferablyconnected, as by suitable gearmg, to drive a single shaft,from which power may be taken. The movements of the two pistons are sotimed as, preferably, to bring the pistons very close together at theend of the exhaust stroke, to scavenge till These results are obtainedby moving the pistons towards each other, and away from each other, atsuitable times, at their di1f-= ferent. speeds.

The shaft driven by the two crank shafts may, if desired, be ofcomparatively low speed, maki'n a suitahle drive for a low speed highpitch propeller orsc rew.

The admission and exhaust are prefer-- ably controlled by a singlespecial form of sleeve valve; this is arranged at one time to opencommunication between an inlet openingof the cylinder and the spacebetween the two pistons, at another time to open communication betweenan exhaust opening and this space, and at other times to shut off thisspace from both the inlet and exhaust ports of the cylinder.

Various arrangements or combinationsof duplex cylinders of the characterreferred to may be made within the invention, or, of course, an enginemay comprise a single such cylinder.=

Other features and advantages of the invention will be more fullydescribed hereinafter. The objects of the invention include theprovision of various combinations, sub-combinations and ieoture ofconstruction, all as will ,be more fully set forth hereinafter.

A further feature oi the invention is that the cylinder volume may bemade considerably, less at the end of the exhaust.

stroke than it is at the time of the explosion of the charge, at the endof the compresion stroke. The two pistons may, come practically togetherat the end of the exhaust stroke, toefiect scavenging of practicallyi009}, .eihciency',

In order that the invention may be more clearl understood attention ishereb -di rected to the accompanying drawings 'orming part of thisapplication and illustrating one embodiment. of the invention. In the jdrawings Fig. lirepresents a view partly in vertical section andpartly-in front elevation of an engine comprising the invention;

ig. 2 is a diagrammatic top plan view of one arrangement of a pluralityof cylinmatictop plan viewsof modified forms ofarran ment of a pluralityof cylinders connect with a common driven shaft.

Referringto the drawings, a duplex cylinder 1 is illustrated, having twopistons 2 and 3 mounted therein in opposite ends of the cylinder, thecombustion chamber of the cylinder comprising the space, 4, between thetwo pistons. The lower piston 2 connected by'connecting rod 5 to a crank6 of the crankshaft 7, while the upper piston 3 is connected by aconnecting rod 8 tov the crank 9'of1a crank shaft 10. Crank 9 of theupper crank shaft, as shown, has a less radius or throw than crank .6 ofthe lower crankshaft. Connecting rods 5 and 8 may be rotatably mountedat their inner ends ontransvers'e ins 11 and 12 respectively, carried bypistons 2 and 3. Crank shaft is'- intended torotate at a fraction of thespeed of crank shaft 7, crank shaft 10 rotating at one-half of the speedof crankshaft 7 in the construction illustrated in the drawings.Themanner in which the volume of combustion chamber 4 will be varied bythe movements of pistons 2' and 3 will be describedhereinafter.

The engine illustrated operates on the four cycle principle.

Cylinder 1 is formed in a casting having a suitable water jacket" 1?.The cylinder castingh as an'opening13 extending therethroug this being te exhaust opening,

and an opening 14 which serves as an inlet opening. As indicatedfthesetwo openings may be located adjacent to a plane midway between the twoends of'the cylinder, the

exhaust opening 13 being shown as being somewhat above the median plane,that is on theside of the said plane towards the half'speed crank shaft10, while the inlet olpemng 14 is on the other side of said plane, t atis, the side thereof towards the-full speed crank-shaft 7. Asshown-these-two 0 mngs may be separated by a portion 15' oi the lindercasting. The position of the I spark p ug' o'r spark plugs'within thecombustion chamber is indicated at 16. I

The admission of charge to the combus-' tion chamber-and the exhaust ofburnt gases therefrom is preferably controlled by a single sleeve valve17 which is adapted to reciprocate at suitable intervals in the axialdirection of the cylinder. As is indicated in Figs. 4 and 5, valve 17 ispreferably crescent sha ed in cross section and is mounted wit in asimilarly shaped recess 18 formed within one side portion of the bore ofthe cylinder. This recess is so ositioned that the sleeve valve willexten between openings 13 and 14 and the interior ofthe cylinder,pistons 2 and 3 having sliding contact throughout a greater portion ofthe periphery of each against the bore of cylinder 1 and through alesser portion of theperiphery of each against the inner surface of thesleeve valve.

The sleeve valve has a single opening 19 therethrough, as is indicatedin Figs. 1 and 4. This opening 19 is adapted to register in one positionof the sleeve valve with inlet opening 14 and in another position of thesleeve 'valve withexhau'st opening 13, opening 19 corresponding in shapeand size with the inner ends of openings 13 and 14.

The sleeve valve is so controlled as to cause opening 19 to align withopening 14 during the times when the charge, such as the usual gaseousmixture, (or air, ifliquid' fuel is to be injected into the cylinderlater) is tobe taken. in. Opening 19 will align with opening 13 at'alltimes when the exhaust of burnt gases is to take place; and it will bein an intermediate position, out of alignment with both openings 13 and14, that is in alignment with the cylinder wall portion 15 between theopenings 13 and 14, at: times when neither admission or exhaust is totake place as during the compression and'workingof piston 2.

The reciprocating movement of sleeve 17, desi nod to cause the opening19 in the sleeve to fiign with openings 13 and 14 at the proper times,is preferably imparted to the sleeve by means of a suitably shaped cam.

In the construction shown in Figures 1 and 6 of the drawings, crankshaft 10 is provided with a disc concentrically mounted thereon, havinga cam groove 21 formed in the face thereof. The crescent-shaped sleeve17 carries at its upper end apin 22 which extends into this groove. Thecam groove is so shaped as to give the sleeve the desired movement, aswill be more fully described hereinafter. 1

Crank shafts 7 and 10 are preferably both connected to drive the sameshaft, 23, from which power maybe taken. As shown in the" drawings,crank chaft 7 may be conne'cted to drive shaft 23 by means of beveledpinions 24 and '25, mounted on crank shaft 7 and the driven shaft 23respectively. Similarly crank shaft 10 is connected to shaft 23 by meansof beveled pinion 26 on crank shaft 10 which meshes with beveled gear 27on driven shaft 23. The gear ratios between gears-24 and 25, and 26 and27, are such that crank shaft 10 is rotated at one half the speed ofcrank shaft 7. As shown in the drawings gears 25 and 27 on shaft 23 areof the same size, while pinion 24 has a pitch diameter one half of that.of pinion 26. Any suitable arrangement may be used which will give thedesired result. It is, however, sometimes desirable, as previouslystated, to have shaft 23 of comparatively low speed, and ac-- oordinglythe gear 25 is shown as considerably larger than gear 24 meshingtherewith so as to drive shaft 23 at a slower speed than crank shaft 7In Fig. 1 a second duplex cylinder 1 is illustrated, this containingmechanism which may be exactly the same as that contained withincylinder 1. The upper crank shaftv of cylinder 1, corresponding to.crank shaft 10 of cylinder 1, is provided with a beveled pinion 28similar to pinion 26 and also meshing with beveled gear27. Similarly thecylinder 1 has a lower crank shaft corresponding to crank shaft 7 andhaving a beveled pinion 29 similar to pinion 24 and also meshing withpinion 25 on shaft 23.

Crank shafts 7 and 10 may be provided with crank cases 30 and 31integral with or secured to thecylinder casting 1, crank shafts 7 and 10being rotatably mounted in bosses or enlargements 32, 32, and 33, 33,formed on the crank case portions of the cylinder casting. The drivenshaft 23 may be rotatably mounted in bearings 34 formed on spiders orarms 35 extending from cylinders 1 and 1.

The operation of the engine will be. more clearly understood from thediagram illustrated in Fig. 3 inwhich the travel of the lower or fullspeed piston 2 is indicated by the line 36. The travel of the upper orhalf speed piston 3 is indicated by the line 37. The horizontal upperdotted lines 38, 38, indicate the upper and lower edges of exhaustopening 13, while the lower horizontal lines 39, 39'represent the upperand lower edges of the inlet opening 14 in the cylinder. The parallellines 40, 40 indicate the upper and lower ed es of the opening 19 in thesleeve during t e movement of the same. For convenience the movement ofthe sleeve is also indicated by the single line 40 which- -are closetogether atthis time.

her space of the cylinder, being very slight.

rection as piston 2.. Piston 3, however, 'moves at only half the speedof piston 2, as

stated. It also has a much less travel in each direction than has piston2 because of the fact that crank 9 of crank shaft 10 travels about acircleof much less radius than does crank 6 of crank shaft 7.

Cranks 9 and 6 are also disposed at different angular'positions inrelation to their stroke circles so that one of the pistons will reachits :dead center positions before the other. Thus, as is shown in thediagram, piston 3 will reach its lower dead center positionapproximately at the point 42. Piston 2 will reach its lower dead centerposition somewhat later, approximately at the point 43.

Piston 2 will reach its next upper dead center position at point 44 onthe diagram at 1 which time piston 3 is still moving on its outwardstroke, .its position at this time being indicated by point 45 on line37.

Piston 3 reaches its outer dead center position "at approximately thepoint 46 on line 37 at which time piston 2 has not quite completed itsnext outward stroke, piston 2 reaching its lower dead center slightlyafter piston 3 reaches its upper dead center, this lower dead centerposition of piston 2 being represented by point 47 on line 36. Piston 2completes its following upward stroke when the point 48 on line 36 ofthe diagram is reached, at which time piston 3 is moving inwardly, itsposition being indicated by point 49 on line '37, this point being closeto point 48, indicating that the two pistons Points 48 and'49 at theleft hand edge of the diagram, representing the starting points of lines36 and 37 respectively, represent, of course, the same positions ofpistons 2 and 3 as do the points 48 and 49 at the ends of lines 36 and37.

The distance between the working faces of pistons 2 and is representedby the vertical distance between lines 36 and 37, at any point in thetravel of the pistons. As will be explained, the admission-of freshcharge takes place during the interval marked Admission on the diagram,followed by the periods indicated by the words Compression, lVorking,and Exhaust. Each of these periods corresponds approximately to a strokeof full speed piston 2. The maximum distance between the two pistonsduring the admission stroke is indicated by the vertical line 4343connecting points on lines 36 and 37. This, it is noted, is less thanthe maximum distance between the pistons during the exhaust stroke,indicated by the vertical line 47- 4? The charge is ignited at thebeginning of the working stroke, at which time the distance between thetwo pistons is represented by the vertical line it-4:5. The exhaust iscompleted when pistons 2 and 3 have apthe. cycle of the engine isrepresented as commencing at the point indicated by l, at

the end of the exhaust stroke.- At this moment piston '2 is at its upperdead center position, represented by point 48 on the diagram. Piston 3is close thereto, its position being represented by point 49 Sleevevalve 17 at this time is in its uppermost position, in which its opening19 would open communication between exhaust port 13 and the interior ofthe cylinder, except for the fact that theupper edge of piston 2 isslightly above opening 19 so that the latter is closed,

Piston 2 moves downwardly from the position referred to its downward oroutward travel being represented by the downwardly extending portion ofline 36 which terminates at point 43. The half speed piston 3 at the isame time'is moving in the same direction,

that is to say,iit is moving on itsinwa-rd or downward stroke, whichterminates at the lower dead center position, indicated by point 42 online 37. The volume of the space between the two pistons will constantlyincrease during this movement of the pistons because of the fact thatwhile both pistons are moving in the same direction piston 2 is movingmore rapidly,-and also because of the fact that piston 2 has a longerstroke than piston 3. i

The sleeve valve begins to move downwardly at or about the time thatpiston 2 leaves its upper dead center position l. As stated, the travelof the sleeve valve is indicated by the parallel lines -10, ll), andalso for convenience by the single line 40 T he upper edge of piston 2and the upper edge opening 19 in the sleeve valve will moveapproximately together as they descend below exhaust opening 13, so thatcommunication between the exhaust port 13 and the inte rior of thecylinder will not be opened at this time. Opening 19 in the sleeve valvedescends until it opens communication with the inlet port 14; As isindicated by the ars er diagram, the lower edge of opening 19 in thesleeve valve passes downwardly past the upper edge of inlet opening 14when the point indicated by TI is reached in the diagram. At this timethe upper edge of the lower piston 2 has descended below opening 19, asis indicated by the line 36, so that communication is opened betweeninlet port 14 and combustion chamber 4 of the cylin-- der, when opening19 aligns with the inlet port.

The sleeve valve descends until its opening 19 completely aligns withthe inlet port 14 of the cylinder, as is indicated at the point marked50 on the lower one of the two lines 40 in the diagram. The sleeve valvewill be held stationary in this position until the point 51 on thelowerot the two lines 40 is reached, at which time the sleeve valvebegins again to move upwardly, opening 19 of the sleeve valve passingentirely out of communication with inlet port 14; when the positionindicated by HT is reached. A charge of gaseousmixture is accordinglyadmitted to the combustion chamber during the period represented by thedistance between points l1 and ill, the entire admission period beingrepresented bythe cross hatched area 52. It will be noted that piston 2moves downwardly, more rapidly than does piston 3, between positions 11and H, before the fresh charge begins to be ad-- mitted, and durin thisperiod a high vacuum will be pro need within the combus tion chamber,the burnt gases of thia previous charge having been practicallycompletely expelled from the cylinder when the position 1 was reached,as .will be explained hereafter. As the piston 2 continues to movedownwardly more rapidly than does piston 3 during the admission strokethis vacuum will be increased throughout the downward stroke of piston 2represeiited by-the portion of line 36 which terminates at point 43.

Beginning with point 43 on line 36 piston Y 2' commences its next inwardor upward stroke which terminates when position 44;- on line 36 isreached. During this time piston 3 is also moving on its upward oroutward stroke, that is in the same direction as piston 2, but at a ratewhich isconsiderably less than that at which piston 2 travels.Accordingly the volume of the combustion space between the two pistonswill be continually ecreased during the upward move ment of piston 2,terminating at point 44 and the intaken charge will be compressedbetween the two pistons until piston 2 reaches the position 44, which isdenoted at the bottom of the diagram by the indication IV. The explosionor firing; of the compressed charge takes place at or about the upperdead center position 44- of piston 2 'at whichtime the nest outward ordownward stroke of piston 2 begins,

till

The sleeve valve,havi closed inlet port 3 1st at position HI, rises sightly to its position intermediate ports 14 and 13, indicated by point53 on the lower of the two lines 40 in the dia ram. The sleeve valve isheld stationary In this intermediate position until point on the diagramhas been reached. The sleeve valve is thus held stationary, betweenpoints 53 and 5a during the greater part ofthe compression stroke ofpiston 2 and during the greater part of the succeeding working orexpansion stroke of piston 2.

Piston 2 starts its working or expansion stroke, as stated, at the point44 on the diagram, this outward movement of piston 2 terminating atpoint 471' Figure 1 of the drawings represents the position of the partsat the moment when the charge is fired, and when piston 2 is about tostart on its working stroke. During the outward or downward travel ofpiston 2 piston '3 is also moving on its outward or upward stroke, untilthe upper dead center position of piston 3 is reached, at point 46. Asis =2 shown by the diagram, piston 3 moves only a slight distance on itssucceeding inward or downward stroke between the points 46 and 47 atwhich time piston 2 completes its downward stroke. Accordinglythe volumeof the combustion chamber space between the two pistons will increaserapidly during all the time that the expansion of the exploded chargetakes place. Also, as has been previously stated, the gases are expandedat the end of the working stroke of piston 2 to a volume considerablygreater than the maximum volume occupied by the charge during theadmission stroke of piston 2.

The sleeve valve beginsto move upwardly, that is towards the exhaustport 13, at point 54: on the diagram. Communication between thecombustion chamber and the exhaust.

port is established shortly thereafter at about the point indicated at46 in the dia. gram, when opening 19 in the sleeve valve begins toregister with exhaust opening 13. Opening 19 will register completelywith exhaust port 13 shortly thereafter,.valve 17 then being heldstationary in its upper position until point V l, which is the same aspoint l, is reached.

During the exhaust from the combustion chamber full speed piston 2 hascompleted it downward stroke and moves upwardly on its succeeding inwardstroke. At the point marked 55 on line 36 the upper edge of piston 2begins to move past opening 19 in the sleeve valve. At the end of thisupward stroke of piston 2, represented by point 48 on the diagram,piston 2 has completely covered opening 19 in the sleeve valve. thusclosing the exhaust from the combustion chamber. The period of exhaustis indicated by the cross hatched area 56 onthe diagram, the exhaustextending from point 46 to point48.

During the upward travel of 1 piston 2 from position 47 to position 48,that is the upper dead center position of piston 2, piston 3 is movingon its inward or downward stroke. The exhaust port having been open allof this time the burnt gases are scavenged or driven out of thecylinder, positively, by the movement of the twopistons towards eachother. As the two pistons come almost together at positions 48 and 49,the burnt gases will be scaven ed or driven out of the cylinder with ane ciency which may be practically 100%, before the period or admissionof fresh mixture into the cylinder is again started.

The movement of the sleeve valve, as described, may readily beaccomplished b properly shaping the cam groove 21 witi which pin 22 onthe sleeve valve co-acts. Referring to Fig. 6, the cam disc may beconsidered as rotating in a counter clockwise direction. When pin 22 isat oint 48 in the cam groove,-piston 2 isjust eaving its upper deadcenter position I. The cam groove is so shaped as to force pin 22downwardly, from point 48 of the groove to approximately point 5O atwhich time inlet opening 14 is fully uncovered. The cam groove has aportion substantially concentric with the crank shaft from point 50 topoint 51, where the direction of the cam groove changes so as to raisepin 22 slightly.

\Vhen point 53 has been reached by pin 22 opening 19 in the sleeve valvewill have reached its intermediate position, and a concentric portionof'the cam groove follows, until point 54 has been reached when the camgroove again moves inwardly from its concentric path so as to againraise pin 22 to bring opening 19 in the sleeve valve into alignment withexhaust, port 13. centric portion of the groove then folilows, to holdthe pin stationary until point 48 is against reached. i

As has been stated engines constructed in accordance with the inventionmay comprise one or more cylinders and the cylinders ma be grouped orarranged in various ways. in which six cylinders 1 are mounted at equalangular distances about the driven shaft 23. The driven shaft isrepresented as having a beveled gear 27 thereon with which the beveledpinions 26 on the upper crank shafts of the various cylinders mesh. Thismay be considered as the same arrangement as that shown in Fig. 1, Fig.1 being taken on a section which may be considered as extending alongthe axis of the upper crank shaft of any cylinder and of the c linderdiametrically opposed thereto. he crescent shaped sleeve valve or eachcylinder is represented at 17 a pin 22 on each A con llllll) Jill) nFig. 2 is indicated a construction sleeve valve being indicated ascooperating with the cam groove on the crank disc 20 of the upper crankshaft of that cylinder. With such an arrangement power will be appliedto the driven shaft 23 at equally spaced points around the periphery ofshaft 23 both at the level of the upper crank shaft and at the level ofthe lower crank shaft.

In Figure 7 a different multi-cylinder engine arrangement is indicatedin which the various duplex cylinders 1 are mounted in straight linerelation with the driven shaft 23 parallel to all of the cylinders. Inthis case all of the sleeve valves li' 'are positioned in the directionof the crank shafts. The cylinder 1 at the extreme left of the diagramis represented as having its sleeve 17 at the extreme left, connected bypin 22 to the crank shaft 10 to which the next adjacent cylinder 1 isalso connected. This second cylinder has its sleeve valve 17 mounted atthe right of the cylinder, and connected by its pin connection 22 tocrank shaft 10 this crank shaft being connected by beveled pinion 26 tothe beveled gear 27 on shaft 23 The two'cylinders indicated at the rightof the driven shaft 23 are similarly connected. With this arrangementthe pair or other plurality of cylinders at the left of the driven shaftall drive the same pair of crank shafts which impart power to the shaft23 at one side of the same while the plurality of cylinders to the rightof the driven shaft operate a pair of crank shafts which apply power tothe shaft 23 on the opposite side of the same.

A somewhat different arrangement is shown in Figure 8 in which cylinders1 are mounted in straight line relation with the driven shaft 23?parallel thereto and situated between the same, the same as has beendescribed in connection with Figure 7 In the arrangement shown in Figure8, however, the sleeve valves 17 of the cylinders are not positioned inalignment with the crank shafts, but are mounted on the sides of thecylinders,- 90 away from the positions indicated in Figure 7. In thiscase the pin 22 cooperating with the crank disc 20 of the upper crankshaft of any cylinder may be connected by an angular connection 57 withthe sleeve valve 1'? of that cylinder. -With such an arrangement all ofthe cylinders at one side of the driven shaft 28 cooperate with the sameupper and lower crank shafts, while all of the cylinders at the oppositeside of the driven shaft coop erate with the same pair of upper andlower crank shafts in the same manner as has been described inconnection with Figure 7. This arrangement permits the cylinders to bemore closely spaced than does the arrangement shown in Fig. 7

In connection with the constructions which have been described. it willbe noted rality of valves commonly operated thereby.

in usual prior constructions, are eliminated. The only moving parts are.the two'pistons and one sleeve valve in each cylinder together with thetwo crank shafts and connec* tions between the same and the two pistons.both crank shafts being power transmitters.

Power may be transmitted very effectively to the driven shaft andapplied to the latter at points so distributed as to produce a smoothand even application of power thereto. The driven shaft may be operatedat a reduced speed in comparison to the speeds of the crank shafts, asis desirable for example where a screw or propeller having high pitchand low speed is to .be operated.

The mechanism described enables the two pistons to come practicallytogether at the end of the exhaust stroke, so that the exhaust of theburnt gases will be very positive and in some cases may be madepractically 100% efiicient. The arrangement is such that the volume ofthe combustion chamber is much less at the end of the exhaust strokethan it is at the time of the firing of the compressed charge. The veryeflicient scavenging, permits a correspondingly efficient dimensions.that is to say. the burnt gases having been entirely expelled, thecylinder will be filled practically entirely with fresh gases during theperiod of admission. Because of this construction an engme built inaccordance with the invention will develop greater power than an enginehaving the same stroke, bore of cylinder and other admissions, in whchthe scavenging and admission of fresh charge are not so efiicient.

Because of the fact, as described, that both pistons move in the samedirection during the admission stroke but move in opposite directionsduring the explosion stroke. the result is obtained of expanding theexploded charge to a greater volume than the maximum volume of thecylinder during the admission stroke. In prior engines so far as agreater extent and increases the eiiicienev I of the enginecorrespondingly. According- 1y. it maybe said that the presentconstruction permits a greater output of power in comparison with anengine operating upon the same volume of charge in which such in 1nevaeov creased expansion is not obtained. Accordingly, the economy ofthe construction described is considerably enhanced. The constructiondescribed and illustrated enables a production of power which may be,for example, from 15% to 25% greater than the power obtainable from asimilar unit consuming the same amount of fuel. Likewise, of course, ifthe same power be devel oped as a corresponding engine which does notexpand the compressed charge in the manner described, the fuelconsumption will be correspondingly decreased, so that there may be insuch a case a saving of fuel of, for example. from 15% to 25%.

It will also befnoted that the exceedingly etiicientexhaust which hasbeen described enables the maintenance of an average working temperatureconsiderably less than that employed in prior engines, in which no suchefficient exhaust is obtainable.

It will also be noted that the cylinder may be fully charged with purefresh mixture at every desirable rate of engine speed, because of theextremely efiicient scavenging and the extremely efiicient production ofvacuum in the cylinder during the period of admission.

It should be understood that while I have described certain forms andfeaturesof the invention with particularity, the invention is notlimited to the exact details which have been described, but that variousmodifications may be employed, as will. be clear to those skilled in theart, after reading this specification, the. scope of the invention beinindicated by the accompanying claims.

hat I claim is:

1. In an internal combustion engine, the combination of a cylinder, apair of pistons therein. movable away from and towards each other toestablish a combustion chamber between them, one of said pistons havingsuccessive strokes during which admission to, compression in, expansionin, and ex- -haust from, said chamber take place, means comprising a.single slide-valve for admitting a gaseouscharge to the combustionchamber. and exhausting burnt gasesltherefrom at appropriate times, andmeans for so moving said, pistons that the maximum volume of theombustion chamber will be greater during the working or expansion strokethan it is during the admission stroke of the pistons.

2. In an internal combustion engine, the combination of a cylinder,means comprising a single slide valve for admitting charge thereto andexhausting burnt gases therefrom periodically, two movable memberstherein, one of the same being a piston having successive admission,compression, expansion and exhaust strokes, and means for permittingsaid movable members to so move that the ignited charge will expand togreater volume in the cylinder during the combination of a cylinder, 9.pair of pistons therein, movable away from and towards each other toestablish a combustion chamber between them, means comprising a singleslide valve for admitting charge to and ex hausting burnt gases fromsaid chamber periodically, and means for so moving said pistons thatthey will move towards each other during practically the entire periodof exhaust, to drive out the burnt gases, and will come almost intocontact with each other at the end of the exhaust.

at. In an internal combustion engine, the combination of a cylinder, apiston and an abutment therein, relatively movable towards and away fromeach other to establish a combustion chamber between them, meanscomprising a single slide valve for admitting charge to and exhaustingburnt gases from said chamber periodically, and means for causingrelative movement between saidpiston'and abutment to take place in suchmanner as to vary the distance between them while said piston hassuccessive admission, compression, working and exhaust strokes, therelative movement being so arranged that the distance between the pistonand abutment will be greater at the end of the compression and thebeginning of the working stroke than at the end of the exhaust stroke.

5. In an internal combustion engine, the combination of a cylinder, apair of pistons therein,movable away from and towards each other toestablish a combustion chamber between them, means for admitting chargeto and exhausting burnt gases from said chamber periodically, saidcylinder having successive admission, compression, working, orexpansion, and exhaust periods, and means for so moving said pistonsthat the distance between them will be greater at the end ofthecompression and the beginning of the working or expansion period thanat the end of the exhaust period, and that the maximum distance betweenthem will be greater during the working or expansion period than duringthe admission period.

6. In an internal combustion engine, the combination of a cylinder, apair of pistons therein, movable away from and towards each other toestablish a combustion chamber between them, means for admitting chargeto and exhausting burnt gases from said chamber periodically, saidcylinder having successive admission, compression, working or expansion,and exhaust periods, each occupying substantially one stroke of one ofsaid pistons, and means for so moving said pistons that they will movein the same direction throughout the greater part of the admission eachother to establish a combustion chamber between them, means foradmitting charge to and exhaustin burntgases from said chamber periodicaly, said cylinder having successive admission, compression, workingorexpansion, and exhaust periods each occup ing substantially one strokeof one of sai pistons, and, means for so moving said pistons that theywill move in the same direction, one traveling furtherand faster thanthe other, throughout substantially all of the admission period-and inopposite directions during the working or expansion period.

8. In an internal combustion engine, the combination of a cylinder, 'apair of pistons therein, movable away from and towards each other atdifierent speeds to establish a combustion chamber between them, saidcylinder having inlet and exhaust ports, a

single slide valve ada ted to control communication between said portsand combustion chamber, at suitable times, crank shafts to which saidpistons are connected, and means opera'tively connecting one of said'crank shafts and said valve.

9. In an internal combustion engine, the combination of a cylinderhaving separated inlet and exhaust ports, pistonmeans in said cylinder,a single sleeve valve controlling said ports and having a single openingtherein and means for operating said sleeve valve, to cause it to moveinto a position to open said inlet port by aligning said openingtherewith, then into position to close both ports and to remainstationary in such position for an interval, and then into position toopen said exhaust ort by aligning said opening therewith, said operationbeing repeated cyclically.

10.. In an internal combustion engine, the combination of a cylinderhaving separated inlet and exhaust ports, piston means in said cylinder,a single valve having a sigle opening therethrough controlling saidports, and means for operating said valve, to cause it to move into apositlon to open said inlet port by aligning said opening therewith,then into'position to close both ports and to remain stationary in suchposition for an interval, and then into position to open said exhaustport by aligning said opening therewith, said operation being repeatedcyclically. v

11. In an internal combustion engine, the combination of a cylinderhaving separated inlet and exhaust ports, piston means in said cylinder,a single valve having a single opening therein controlling said ports,

and means for operating said valve, to cause it to move in one directionfrom a position in which both ports are closed to a position in whichone of said ports is opened by aligning said opening therewith, then inanother direction to a position in which the other port is opened byaligning said opening therewith, and then back to the position in whichboth ports are closed, said operations being repeated cyclically.

12. In an internal combustion engine the combination of a cylinderhaving separated inlet and exhaust ports, piston means in said cylinder,a single valve having a single opening therein controllin said ports,and means for operating said va ve, to cause it to move in one directionfrom a position in which separated inlet and exhaust ports, a piston insaid cylinder, a crank shaft connected to said piston and having a camthereon, a crescent shaped sleeve valve having a single openingthereincontrolling said orts and means for operating said valve fromsaid cam to cause said single opening to align with said inlet andexhaust ports respectively, with periods of movement and periods ofpause.

' 14. In an internal combustion engine, the combination of-a pluralityof cylinders, having parallel axes arranged in .a circle, a pair ofpistons in each of the same, movable away from and towards each other, aseparate crank shaft for each piston, connected therewith, extendingradially of said circle, a driven shaft at the center of said circle,and gear connections between each crank shaft and said driven shaft, thegear connections between said driven shaft and the crank shafts adjacentone end of each cylinder all having the same gear ratio, and the gearconnections between said driven shaft and the crank shafts adjacent theopposite end of each cylinder all having the same gear ratio, differ"ent from the first named gear ratio.

15. In an internal combustion engine, the combination of a cylinder, apair of pistons therein, movable towards and away from each other, crankshafts at opposite ends of the cylinder to which said pistons arerespectively connected, one of said crank shafts being' rotatable at afraction of the speed of the other, said cylinder having inlet andexhaust ports, a single sleeve valve having a single opening therein andmeans for operating said valve to cause it to control admission ofcharge through said inlet port into the space between the istons, andexhaust of burnt gases from said space through said exhaust port, atappropriate times.

16. In an internal combustion engine, the combination of a cylinderhaving axially separated inlet and exhaust ports, a pair of pistonstherein, movable towards and away from each other, a crescent shapedsleeve valve 7 having a single opening there,- in, slidably mountedbetween said cylinder and pistons, said valve controlling both saidports, and means for operating said valve at appropriate times.

17. In an internal combustion engine, the combination of a cylinder,having axially separated inlet. and exhaust ports, a pair of pistonstherein movable away from and towards each other to establish acombustion chamber betweenthem, a single sleeve valve situated betweenthe cylinder wall and said pistons, having asingle opening therein,controlling said ports, means for operating said valve to cause it toopen and close said ports at suitable times, said cylinder havingsuccessive admission, compression, working, or expansion, and exhaustperiods, and means for so moving said pistons that the distance betweenthem will be greater at the end of the compression and the beginning ofthe working or expansion period than at the end of the exhaust period,and that the maximum arated inlet and exhaust ports both locatedadjacent the central portion of the length of the cylinder, a pair ofpistons therein, movable away from and towards each other to establish acombustion chamber between them, a single slide valve for admittingcharge to and exhausting burnt gases from said chamber periodically, andmeans for somoving said pistons that they will move towards each otherduring practically the entire period of exhaust, to drive out the burntgases through said exhaust port, and will come almost into contact witheach other at the end of the exhaust.

In testimony whereof I have 'i ed my name to this specification, at Newfo i'k city, N. Y., this 11 day of April, 1922.

CHARLES J. TOTH.

